THIS INVENTION relates to ground slicing apparatus which may be utilized for aeration of grass surfaces, such as lawns, golfing greens and bowling greens.
Aeration of grass surfaces can be carried out by scarifying, coring and/or slicing operations. Scarifying of golf greens is a time consuming process which is usually only carried out on a seasonal basis and involves the use of dethatching apparatus which involves removal of a top section of grass or turf in rows 25-40 mm apart and at a depth of between 3-5 mm. Scarifying is a necessary pre-requisite for golf greens in that it is necessary to reduce the thatched surface layer or grass density. Unless such reduction is carried out, golfing greens will develop a matted surface layer which is substantially impervious to flow of liquid therethrough and thus inhibits moisture or fertilizer from reaching the root system.
Scarifying of golfing greens as described above is disadvantageous in that it is a messy operation leaving grass clippings and dirt on the surface of the golfing green.
After scarifying, the greens require top dressing which leaves the surface of the grass at an undesirable consistency or very uneven state having surface irregularities thereby presenting a bumpy track for passage of a golf ball which makes the ball difficult to putt in a straight line as the ball will frequently deviate or wander off-line.
Conventional scarifying apparatus includes a main frame having ground engaging wheels which are driven by drive means, such as an internal combustion motor mounted on the main frame. There is also usually included a sub-frame which may be raised or lowered relative to the main frame. There is also included an axle connected to the drive motor by a suitable drive train so as to be rotated thereby when required. There was also included a plurality of circular cutters mounted to the axle at spaced intervals which penetrated the ground when the sub-frame was in the lowered position to carry out the aforementioned dethatching operations. Scarifying apparatus of this type is described in Australian Patent Specification No. 53371/79.
Coring of golfing greens is carried out by drilling or punching the ground surface with a plurality of hollow tubes which after subsequent withdrawal from the ground contain solid cores of vegetation leaving a plurality of holes. Usually the hollow tubes penetrate the ground 50-100 mm and are attached to a support frame which reciprocates upwardly and downwardly relative to a main frame of the coring apparatus. The main frame may be connected by a right angle gear mechanism to a drive motor mounted on the main frame. The purpose of coring is to relieve compaction of the golfing green surface and facilitates top dressing to be dropped into the holes imparted to the green. A conventional coring apparatus is described in International Publication No. WO93/119580 which in lieu of hollow tubes uses rotational drilling members which are rotated by an endless chain associated with a coring head attached to one end of the main frame.
Ground slicing is usually carried out by a roller assembly having a plurality of slicers or cutters fixedly attached thereto which sliced the ground upon rotation of the roller assembly. Usually the roller assembly was free-wheeling and was rotated when attached to a drawbar of a tractor. A tumbling slicer of this type is described in Australian Patent No. 672352 and was disadvantageous in that the tractor was usually not allowed to travel on golfing greens or, if it did, left undesirable marks due to movement of the wheels of the tractor on the green. Also, the cutters or slicers attached to the roller also imparted undesirable marks or tracks on the green.
Usually, in relation to maintenance of golfing greens, it was normally necessary to carry out a scarifying. operation twice per year and a coring operation twice per year. Such maintenance was relatively expensive and time consuming and, in some cases, meant that setting appropriate dates for tournaments was relatively difficult because it usually took a period of time of 3-4 weeks for the golfing green to recover from the scarifying or coring operation to achieve a true even surface.
Reference is also made to AU 254567 which refers to a combined compacting roller/ground aerator wherein the ground aeration apparatus is located behind both the drive roller and a smoothing roller or idler roller (i.e. having regard to one direction of travel). This particular apparatus is considered to be disadvantageous in that after one traverse any soil disturbance will remain in the ground and it is therefore necessary that a further traverse be made over the same ground to remove the soil disturbance by operation of the driven roller. Also, in this apparatus, in order to adjust the position of the ground aeration apparatus, it was necessary to undo a bolt when the apparatus was at rest and adjust the-ground aeration apparatus a new position which could be a disengaged position or an operative position where the ground aeration blades penetrate the ground. This arrangement was also found to be time consuming and cumbersome.
It therefore is an object of the invention to provide ground slicing apparatus which may alleviate one or more disadvantages of the prior art described above.
Ground slicing apparatus of the invention includes a main frame supporting:
(i) a drive roller;
(ii) at least one smoothing roller,
(iii) slicing means located intermediate the drive roller and the said at least one smoothing roller wherein said slicing means comprises an axle having a plurality of slicer blades mounted thereto at spaced intervals along the axle wherein said axle is subject to rotation so that the slicer blades penetrate the ground in use;
(iv) a sub-frame carrying the axle which is movable from. an inoperative position clear of the ground to an operation position whereby the slicer blades penetrate the ground; and
(v) remote-controlled pressurizing means maintaining pressure on the axle in the operative position to firmly retain the axle in the operative position.
Each of the slicer blades may be rigidly attached to the support axle and, in this regard, the support axle may be rotated through a suitable drive train being associated with a drive motor mounted on the main frame. Alternatively, the support axle may be free-wheeling so that it rotates upon ground contact.
The drive train may therefore comprise a drive sprocket or pulley having a belt drive or chain drive which is drivably connected to the drive means such as a drive motor located on the main frame. Usually a gear box or reduction gear is interposed between the drive motor and the sprocket or pulley.
In one form, the cutters or slicer blades may be circular in shape having a plurality of peripheral teeth. In another arrangement, the cutters may be in the shape of a rectangle or triangle or any other geometrical shape which Includes a plurality of spaced points or apices. Preferably, in this arrangement, each adjacent cutter is offset relative to each other to facilitate rotation of the support axle.
The drive roller may be directly coupled to the drive motor through a suitable gear box which is located on the main frame, Preferably the drive roller has stub axles or a single axle which engages with bearings located at each end of the drive roller. There also may be included an undercarriage having attached thereto one or more, preferably a plurality, of the smoothing rollers which are preferably each adapted for free-wheeling upon ground contact. Each of the smoothing rollers may be provided with stub axles mounted for idler rotation with suitable bearings located in the undercarriage.
To enhance the pivotal movement of the sub-frame relative to the main frame, the sub-frame may be provided with opposed longitudinal frame members or shafts which are attached directly to the main frame or, more preferably, to bearings associated with the drive roller as described above.
There also may be provided actuating means for actuating movement of the auxiliary frame from the operative to inoperative position and vice versa and this may comprise an actuating handle which is connected to the sub-frame through linkage means. In one form, the linkage means may comprise a connection rod rigidly attached to the handle which is suitably substantially vertically oriented which connection rod is also attached to a foot slidably mounted to the sub-frame or, more preferably, to a support housing attached to or integral with the sub-frame. Preferably the actuating means is such that the linkage means provides an overcentre locking action on the sub-frame in the operative position. Therefore, the foot may constitute one form of pressurizing means